Low back pain is pain, muscle tension, or stiffness localized below the costal margin and above the inferior gluteal folds, with or without leg pain (sciatica).1 It may be acute or chronic (persisting for 12 weeks or more).2 Nonspecific low back pain is low back pain not attributed to a recognizable pathology, such as infection, tumor, osteoporosis, rheumatoid arthritis, fracture, or inflammation.1 This review excludes low back pain or sciatica with symptoms or signs at presentation that suggest a specific underlying condition.

Incidence/Prevalence

More than 70 percent of people in developed countries will experience low back pain at some time in their lives.3 Each year, 15 to 45 percent of adults suffer low back pain, and one in 20 people present to a hospital with a new episode. Low back pain is most common between 35 and 55 years of age.3

Etiology/Risk Factors

Symptoms, pathology, and radiologic appearances are poorly correlated. Pain is nonspecific in about 85 percent of people. About 4 percent of people with low back pain in primary care have compression fractures and about 1 percent have a tumor. The prevalence of prolapsed intervertebral disc is about 1 to 3 percent.3 Ankylosing spondylitis and spinal infections are less common.4 Risk factors for the development of back pain include heavy physical work, frequent bending, twisting, lifting, and prolonged static postures. Psychosocial risk factors include anxiety, depression, and mental stress at work.3,5

Prognosis

Acute low back pain is usually self-limiting (90 percent of people recover within six weeks), although 2 to 7 percent develop chronic pain. One study found that recurrent pain accounted for 75 to 85 percent of absenteeism from work.6

Clinical Aims

To relieve pain; to improve function; to develop coping strategies for pain, with minimal adverse effects from treatment.2,7

Low back pain is pain, muscle tension, or stiffness localized below the costal margin and above the inferior gluteal folds, with or without leg pain (sciatica).1 It may be acute or chronic (persisting for 12 weeks or more).2 Nonspecific low back pain is low back pain not attributed to a recognizable pathology, such as infection, tumor, osteoporosis, rheumatoid arthritis, fracture, or inflammation.1 This review excludes low back pain or sciatica with symptoms or signs at presentation that suggest a specific underlying condition.

Incidence/Prevalence

More than 70 percent of people in developed countries will experience low back pain at some time in their lives.3 Each year, 15 to 45 percent of adults suffer low back pain, and one in 20 people present to a hospital with a new episode. Low back pain is most common between 35 and 55 years of age.3

Etiology/Risk Factors

Symptoms, pathology, and radiologic appearances are poorly correlated. Pain is nonspecific in about 85 percent of people. About 4 percent of people with low back pain in primary care have compression fractures and about 1 percent have a tumor. The prevalence of prolapsed intervertebral disc is about 1 to 3 percent.3 Ankylosing spondylitis and spinal infections are less common.4 Risk factors for the development of back pain include heavy physical work, frequent bending, twisting, lifting, and prolonged static postures. Psychosocial risk factors include anxiety, depression, and mental stress at work.3,5

Prognosis

Acute low back pain is usually self-limiting (90 percent of people recover within six weeks), although 2 to 7 percent develop chronic pain. One study found that recurrent pain accounted for 75 to 85 percent of absenteeism from work.6

Clinical Aims

To relieve pain; to improve function; to develop coping strategies for pain, with minimal adverse effects from treatment.2,7

Evidence-Based Medicine Findings

Evidence-Based Medicine Findings

Oral Drugs

ANALGESICS (ACETAMINOPHEN, OPIOIDS)

In people with acute low back pain, systematic reviews have found no consistent evidence for the use of analgesics versus nonsteroidal anti-inflammatory drugs (NSAIDs); randomized controlled trials (RCTs) have found that analgesics are less effective than electroacupuncture or ultrasound. In chronic low back pain, RCTs have found that analgesics are less effective than NSAIDs and that tramadol versus placebo decreases pain and improves function.

ANTIDEPRESSANTS

We found no evidence on the effects of antidepressants in acute low back pain. RCTs found inconsistent evidence for the use of antidepressants to relieve pain and depressive symptoms associated with chronic low back pain.

COLCHICINE

We found insufficient evidence on the effects of colchicine in acute or chronic low back pain.

MUSCLE RELAXANTS

Systematic reviews have found that muscle relaxants versus placebo reduce acute low back pain, but have found no significant differences in outcomes versus each other. One small RCT has found that muscle relaxants reduce chronic low back pain in the short term.

NSAIDs

RCTs have found that NSAIDs are more effective than placebo for pain relief and overall improvement in people with acute low back pain. They have found no evidence to distinguish NSAIDs versus each other, no evidence that NSAIDs relieve radicular pain, and conflicting evidence for benefit of NSAIDs versus other treatments (acetaminophen, opioids, muscle relaxants, antidepressants, and nondrug treatments). RCTs have found that NSAIDs are more effective than acetaminophen for overall improvement and more effective than placebo for pain in people with chronic low back pain, and that NSAIDs plus vitamin B were more effective than NSAIDs alone.

Local Injections

EPIDURAL STEROID INJECTIONS

We found no evidence that epidural steroid injections are effective in the absence of sciatica in people with acute low back pain. We found conflicting evidence on the effects of epidural steroid injections in people with chronic low back pain.

FACET JOINT INJECTIONS

We found no evidence about facet joint injections in people with acute low back pain. Two systematic reviews found no evidence that facet joint injections improved pain relief or function in people with chronic low back pain.

TRIGGER POINT AND LIGAMENTOUS INJECTIONS

We found no evidence on trigger point and ligamentous injections in acute low back pain. One systematic review found limited evidence that steroid plus local anesthetic injection of trigger points versus local anesthetic injection alone provided greater pain relief after three months in people with chronic low back pain. It also found limited evidence that phenol versus saline injection of the lumbar interspinal ligament reduced pain and disability after six months.

Nondrug Treatments

ADVICE TO STAY ACTIVE

One systematic review and one subsequent RCT have found that advice to stay active speeds the rate of recovery, reduces chronic disability, and reduces time spent off work in people with acute low back pain. We found no evidence on advice to stay active in people with chronic low back pain.

BACK SCHOOLS

One systematic review and one subsequent RCT have found conflicting evidence on the effects of back schools in people with acute or chronic low back pain. In occupational settings, back schools have been shown to be more effective than no treatment in people with chronic low back pain.

BED REST

Systematic reviews have found no evidence that bed rest is better, but have found evidence that it may be worse than back exercises, physiotherapy, spinal manipulation, NSAIDs, or no treatment in people with acute low back pain. We found no evidence on the effects of bed rest in people with chronic low back pain.

BEHAVIOR THERAPY

Two RCTs have found that behavior therapy reduces acute low back pain more than traditional care or EMG biofeedback. Systematic reviews have found that behavior therapy improves pain and disability compared with no treatment in people with chronic back pain. One review found conflicting evidence about behavior therapy versus other treatments (usual care, back exercises) and found no evidence that one type of behavior therapy is superior to another.

ELECTROMYOGRAPHIC (EMG) BIOFEEDBACK

One small RCT found that EMG biofeedback reduced pain less than cognitive behavior therapy in acute low back pain. One systematic review found conflicting evidence on EMG biofeedback in chronic low back pain.

EXERCISE THERAPY/BACK EXERCISES

RCTs found no evidence that back exercises were more effective than other conservative treatments in people with acute low back pain. Three systematic reviews and additional RCTs have found that exercise therapy is more effective than other conservative treatments in people with chronic low back pain.

LUMBAR SUPPORTS

We found insufficient evidence on the effects of lumbar supports in acute or chronic low back pain.

MULTIDISCIPLINARY TREATMENT PROGRAMS

One systematic review found limited evidence that multidisciplinary treatment, which includes a workplace visit, speeds recovery in people with acute low back pain. One systematic review and three additional RCTs have found that multidisciplinary treatment programs improve pain, functional status, and time to return to work in people with chronic low back pain.

TEMPERATURE TREATMENTS (SHORT WAVE DIATHERMY, ULTRASOUND, ICE, HEAT)

We found insufficient evidence on the effects of temperature treatments in acute and chronic low back pain.

MASSAGE

Two systematic reviews have found no difference in pain, functional status, or mobility with massage compared with spinal manipulation or electrical stimulation in acute low back pain. Two systematic reviews and four subsequent RCTs have found conflicting evidence on massage therapy in chronic low back pain.

SPINAL MANIPULATION

We found conflicting evidence on the effects of spinal manipulation in acute and chronic low back pain.

TRACTION

Systematic reviews and additional RCTs have found no evidence that traction is effective in acute or chronic low back pain.

TRANSCUTANEOUS ELECTRICAL NERVE STIMULATION

We found conflicting evidence on the effects of transcutaneous electrical nerve stimulation in acute and chronic low back pain.

ACUPUNCTURE

We found no RCTs of acupuncture treatment in people with acute low back pain. Two systematic reviews found conflicting evidence in people with chronic low back pain.

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This is one in a series of chapters excerpted from Clinical Evidence,published by the BMJ Publishing Group, Tavistock Square, London, United Kingdom. Clinical Evidenceis published in print twice a year and is updated monthly online. The complete text for this topic, as well as additional information, is available to subscribers at
www.clinicalevidence.com. This series is part of AFP's CME. See “Clinical Quiz” on page 777.